Tire-forming tube.



I. R. RENNER.

TIRE FORMING TUBE.

APPLICATION FILED JUNE II. I9I7.

.1 ,286, 1 07. Patented Nov. 26, 1918.

IIIIIIIIIIIIIIII 'IIIIIIII'I' l/VVENTOR.

By ZfZ/Zennefi M A TTORNEY j pmrnn snares v arana orricn.

IRVIN R'RENN'ER, OF AKRON, OHIO, ASSIGNOR TO THE B. F. GOODRICH COMPANY, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

TIRE-FORMING TUBE.

Original application filed June 17, 1916,

T all whom it may concern Be it known that I, Invm R. RENNER, a

citizen of the United States, residing at Akron, in the county of Summit and State of Ohio, have invented certain new and useful Improvements in Tire-Forming Tubes, of

' which the following is a specification.

This invention relates to inflatable tubes used in the manufacture of pneumatic-tire casings, and especially cord-tire casings. Its object is to'provide a tube, which, when in flated with compressed air or other fluid, will expand circumferentially as a whole without substantially increasing its crosssectional size, and may therefore be em ployed either as the solemeansor in con- 7 junction with other devices for imparting substantially the ultimate shape of a tire carcass which is'initially, in an annular, transversely-flat or cylindrical form.

This application is a division of my aplplication Serial No. 104,289 filed June 1 1916, patented March 12, 1918, No. 1,259,289.

Of the accompanying drawings,

Figure 1 is a plan view showing a fragmen of a tube constructed according to my invention. a I

Fig. 2 is a side elevation, partly in section, showing the deflated tube assembled, together with a gage, within the tire-forming annulus preparatory to shaping the latter.

Fig. 3 is a side elevation, partly in section, showing the tube in its expanded condition and the tire carcass shaped and stretched of making Palmer bicycle tires, each band consisting of a calendered strip of rubber in which are embedded the parallel. twisted threads. Instead offollowing the practice in that art of layin the-threads at an angle to the middle line A of about 45, which results in a tube whose inner circumference Specification of Letters Patent.

Patented Nov. 26, 1918.

gle the tube would be neither expansible nor I contractible circumferentially when inflated, and I therefore lay the threads at an angle, preferably, between 65 and 85, in order to furnish a tube which will elongate on both its inner and outer peripheries, or, in other words, will stretch circumferentially as a wholewhen sufficiently inflated. Fig. 1 shows an angle of substantially 7 0, which I have used successfully in tubes for making tires of 4 section. 1

Figs. 2 and 3 illustrate the preferred manner of using the tube in shaping a cord-tire carcass 14, which-is made initially in the form of a transversely-flat annulus as indicated in Fig. 2, and is supported horizontally upon atable while being shaped. This view represents a two-ply carcass with inextensible bead rings 15 in its edges. 16 is an annular positioning-gage, L-shaped in section, resting upon the table within the tireforming annulus, and forming a shelf of the proper height for sup orting the deflated tube 10 in the middle of said annulus. Tube 10 is provided with an ordinary tire valve 17 to which is connected the air-supply hose 18.

lVhen the tube 10 is inflated, it becomes approximately circular in cr0ss-section and also expands or stretches circumferentially on both its inner and outer peripheries without increasing its cross-sectional dimensions. Thereby the cord annulus is caused to assume substantially its ultimate U-shape by the'distention of its middle portion and the drawing-together of the heads. the tube ex panding until its inner periphery lies substantially'at or outside of the circle of the beads. So far as I am aware, 'my present invention is the first instance of a tire-shaping tube capable of performing this function.

A cylindrical metal hoop 19, having an inner circumference equal to the desired outer circumference of the tire carcass, is slipped over the latter while it is being distended by inflation of the tube 10, so as to act as a gage: and when the carcass has reached this circumference. the hoop 19 is removed and the carcass is ready .for the application of its rubber tread and side strips, breaker strip, fabric bead covers, rubber bead corner strips, and other elements pertaining to the finishing of the raw tire. This finishing may be performed while the carcass remains distended by the air tube 10, which latter permits free access to all sides of the beads in performing the finishing operations thereon. When the raw tire is completed, the tube 10 is preferably deflated and removed and another tube, of the usual construction employed in vulcanizing cord tires, is inserted for the purpose-of holding the tire distended while it is vulcanized in a'suitable mold.

I claim:

1. An annular tire-shaping tube composed of rubber and a series of reinforcing elements substantially inextensible transversely and collectively extensible longitudinally of the tube to permit the circumferential expansion of the latter as a whole and substantially prevent its transverse expansion.

2. An annular tube for shaping tire carcasses, said tube being reinforced with layers of threads wound diagonally thereon in opposite directions at an angle to the middle circumferential line greater than 3. An annular tube for shaping tire carcasses, said tube being reinforced with layers of threads wound thereon in opposite directions at an angle to the middle circumferential line of between and 85.

4. An annular tube for shaping tire carcasses, said tube being reinforced with layers of threads wound thereon in opposite directions at an angle to the middle circumferential line of substantially 5. An annular tube for shaping tire car casses, said tube composed of rubber layers in which are embedded parallel fibrous threads Wound diagonallyin opposite directions in the respective layers at an angle to the middle circumferential line reater than 55 and less than a right angle, said tube having an inflating valve.

In testimony whereof I have hereunto set my hand this 9th day of June 1917.

. IRVIN R. RENNER. 

